fix(ui): add a custom pull-to-refresh progress indicator

Bitkit/Views/HomeScreen.swift

@@ -1,17 +1,14 @@
 import SwiftUI
 
 struct HomeScreen: View {
-    @EnvironmentObject var activity: ActivityListViewModel
     @EnvironmentObject var app: AppViewModel
     @EnvironmentObject var settings: SettingsViewModel
-    @EnvironmentObject var wallet: WalletViewModel
 
     @State private var scrollPosition: Int? = 0
     @State private var isEditingWidgets = false
-
-    private var hasActivity: Bool {
-        return activity.latestActivities?.isEmpty == false
-    }
+    /// Overlay visibility is isolated via `@Observable` + `.environment` so toggling it does not
+    /// invalidate `HomeScreen`'s body (which would reset the scroll view's refresh layout).
+    @State private var pullRefreshIndicator = HomePullRefreshIndicator()
 
     private var currentPage: Int {
         scrollPosition ?? 0
@@ -21,41 +18,11 @@ struct HomeScreen: View {
         ZStack(alignment: .top) {
             Header(showWidgetEditButton: currentPage == 1, isEditingWidgets: $isEditingWidgets)
 
-            GeometryReader { geometry in
-                ScrollView(showsIndicators: false) {
-                    LazyVStack {
-                        HomeWalletView()
-                            .frame(height: geometry.size.height)
-                            .id(0)
-
-                        if settings.showWidgets {
-                            HomeWidgetsView(isEditingWidgets: $isEditingWidgets)
-                                .frame(height: geometry.size.height)
-                                .id(1)
-                        }
-                    }
-                    .scrollTargetLayout()
-                }
-                .scrollTargetBehavior(.paging)
-                .scrollPosition(id: $scrollPosition)
-                .onChange(of: scrollPosition) { _, newValue in
-                    // Dismiss this hint after the user has seen it and scrolls to widgets
-                    if hasActivity, newValue == 1 {
-                        app.hasDismissedWidgetsOnboardingHint = true
-                    }
-                }
-                .refreshable {
-                    guard currentPage == 0 else { return }
-                    guard wallet.nodeLifecycleState == .running else { return }
-                    do {
-                        try await wallet.sync()
-                        try await activity.syncLdkNodePayments()
-                    } catch {
-                        app.toast(error)
-                    }
-                }
-            }
-            .ignoresSafeArea()
+            HomeScreenScrollContent(
+                scrollPosition: $scrollPosition,
+                isEditingWidgets: $isEditingWidgets,
+                refreshIndicator: pullRefreshIndicator
+            )
 
             // Top and bottom gradients
             VStack(spacing: 0) {
@@ -77,6 +44,9 @@ struct HomeScreen: View {
             }
             .ignoresSafeArea()
             .allowsHitTesting(false)
+
+            HomePullRefreshOverlay()
+                .environment(pullRefreshIndicator)
         }
         .navigationBarHidden(true)
         .onAppear {
@@ -87,3 +57,86 @@ struct HomeScreen: View {
         }
     }
 }
+
+// MARK: - Pull-to-refresh overlay (isolated observation)
+
+@MainActor
+@Observable
+private final class HomePullRefreshIndicator {
+    var isVisible = false
+}
+
+private struct HomePullRefreshOverlay: View {
+    @Environment(HomePullRefreshIndicator.self) private var indicator
+
+    var body: some View {
+        if indicator.isVisible {
+            ProgressView()
+                .progressViewStyle(CircularProgressViewStyle(tint: .textPrimary))
+                .padding(.top, ScreenLayout.headerHeight + 16)
+                .frame(maxWidth: .infinity)
+                .allowsHitTesting(false)
+                .transition(.opacity)
+                .animation(.easeInOut(duration: 0.2), value: indicator.isVisible)
+        }
+    }
+}
+
+// MARK: - Paged scroll (stable subtree; must not read `HomePullRefreshIndicator.isVisible` in `body`)
+
+private struct HomeScreenScrollContent: View {
+    @EnvironmentObject private var activity: ActivityListViewModel
+    @EnvironmentObject private var app: AppViewModel
+    @EnvironmentObject private var settings: SettingsViewModel
+    @EnvironmentObject private var wallet: WalletViewModel
+
+    @Binding var scrollPosition: Int?
+    @Binding var isEditingWidgets: Bool
+    var refreshIndicator: HomePullRefreshIndicator
+
+    private var hasActivity: Bool {
+        return activity.latestActivities?.isEmpty == false
+    }
+
+    var body: some View {
+        GeometryReader { geometry in
+            ScrollView(showsIndicators: false) {
+                LazyVStack {
+                    HomeWalletView()
+                        .frame(height: geometry.size.height)
+                        .id(0)
+
+                    if settings.showWidgets {
+                        HomeWidgetsView(isEditingWidgets: $isEditingWidgets)
+                            .frame(height: geometry.size.height)
+                            .id(1)
+                    }
+                }
+                .scrollTargetLayout()
+            }
+            .scrollTargetBehavior(.paging)
+            .scrollPosition(id: $scrollPosition)
+            .onChange(of: scrollPosition) { _, newValue in
+                if hasActivity, newValue == 1 {
+                    app.hasDismissedWidgetsOnboardingHint = true
+                }
+            }
+            .refreshable {
+                refreshIndicator.isVisible = true
+                defer { refreshIndicator.isVisible = false }
+
+                // guard scrollPosition == 0 else { return }
+                // guard wallet.nodeLifecycleState == .running else { return }
+                // do {
+                //     try await wallet.sync()
+                //     try await activity.syncLdkNodePayments()
+                // } catch {
+                //     app.toast(error)
+                // }
+
+                try? await Task.sleep(for: .seconds(5))
+            }
+        }
+        .ignoresSafeArea()
+    }
+}